Abstract: A traffic generating switch (1) has alternative operating modes, namely switching mode and traffic generation mode. The switch includes software modules (10), hardware modules (20), a buffer (30), and a plurality of communication ports (40). The software modules include a switch control module (12), a traffic generator control module (14), and a common platform (16). The switch control module is capable of receiving and forwarding packets, and the traffic generator control module is capable of generating instructions for traffic generation. The hardware modules include a forwarding device (22), a traffic generation device (24), and a media access controlling device (26). When the switch works under traffic generation mode, the traffic generator control module generates instructions for traffic generation according to parameters set by users.